The present invention relates a filling degree gauge for measuring and displaying a residual filling potential of a target area being filled through a target with goods by means of a goods carrier of an agricultural vehicle, especially a discharge spout of a forage harvester.
The invention further relates to an agricultural vehicle comprising a filling degree gauge and a method of controlling filling of a target area, especially an open top container.
In agriculture, as in most businesses, efforts are being made to ensure efficient production. E.g. during harvest efforts are made to ensure quick harvest by providing advanced machines being able to run at a high speed and having a large working width. Further efforts are being made to ensure safe transfer of harvested goods to transport vehicles for transporting the goods from the field. The advanced and fast machines are demanding of control and would lay a heavy burden on their operators if not for automation. Efforts are made to automate harvesting completely, but meanwhile an operator (i.e. a human) performs a number of steering and controlling operations and monitors other operations. In order not to stress the operator or driver unnecessarily monitoring means should be available that facilitate the monitoring as far as possible.
Regarding monitoring transfer of goods to a container during harvest examples of prior art is given below:
DE-A-44 26 059 suggests providing a video camera watching the container and providing a monitor in the driver's cab allowing the driver to watch the loading of the container. Software may be used to recognise the upper edge, i.e. the opening, of the container and keep a spout aimed at the opening.
U.S. Pat. No. 5,575,316 suggests providing a harvester with an optical and/or acoustic range finder for measuring a container to be loaded and measuring the fill levels in the container for automatic filling the container. The control operates an optical or acoustic display when the container has been filled to a certain extend, and other acoustic or optical displays and warning devices are provided. Thus it is suggested to survey the degree of filling, but without transferring the knowledge thereof to a human operator.
U.S. Pat. No. 6,097,425 suggests using a three-dimensionally operating video camera, e.g. an infrared camera, and providing a monitor in the driver's cab, and to show on the monitor                the contour of the upper opening of a container to be loaded,        the corners of the opening,        the point of impact of a stream of goods being loaded into the container,        indications of suggested control operations for redirecting the stream of goods, and        a working signal further provided with an acoustic alarm for warning about loss.        
EP-A-1 344 445 suggests providing a video camera watching a container and providing a monitor in the driver's cab allowing the driver to watch the container during loading. It is suggested to process the image shown on the monitor to optimise its contrast and brightness and it is suggested to provide the image with overlay data such as pointers and text messages.
EP-A-2 020 174 suggests providing a control system with a 3D-camera watching a container to be loaded with goods, the camera and attached software providing for determining positions of the walls of the container, the filling height horizon and characteristic lines and orientation points of the upper side of the container comprising the opening thereof. The purpose of the control system is to relieve the operator as far as possible of the task of monitoring a transfer process. It is suggested to show on a monitor a video sequence showing the container and visualising the filling height horizon and the sidewalls. It is also suggested that critical conditions are indicated by a graphic warning signal. It is thus suggested to show to an operator the filling height horizon, but it demands attention and consideration of the operator to establish the filling degree or the residual filling potential from the filling height horizon. Further it is known to give a warning signal to the operator in critical situations, but not until such situations have actually arisen.